What are the main reasons for antibiotics use in food-producing animals?
Antibiotics are used for the treatment (therapeutic use) of a sick animal or group of animals that have been diagnosed with an infection and/or clinical disease. Additionally, antibiotics may be given to animals that are not currently ill but are at a high risk of acquiring an infection. Control treatment or metaphylaxis aims to prevent the spread of infectious disease to animals in close contact, ones at considerable risk, and those who might already be infected or incubating the disease.
An animal may also be treated with antibiotics after undergoing surgery or injurious trauma – preventive use or prophylaxis. Preventive treatment should only be applied to animals diagnosed at high risk of bacterial disease and not as a routine practice or to compensate for poor hygiene and inadequate husbandry condition.
Besides being used for treatment, control, and prevention, antibiotics have been added to animal feed to promote faster growth by accelerating the rate of weight gain and/or increasing feed conversion efficiency in animals. The use of antimicrobials as growth promoters is being prohibited in a growing number of countries, including in the EU; however, it is still a common practice in many parts of the world.